1. Field of the Invention
The invention relates to a package structure and a manufacturing method thereof. More particularly, the invention relates to a package carrier and a manufacturing method thereof.
2. Description of Related Art
A chip package provides a chip with proper signal and heat transmission paths and protects the chip structure. A leadframe often serves as a carrier of the chip when a conventional wire bonding technique is applied. As contact density in the chip gradually increases, the leadframe is no longer able to further improve the contact density and thus can be replaced by a package carrier which can achieve favorable contact density. Besides, the chip is packaged onto the package carrier by conductive media, such as metal conductive wires or bumps.
In a common light emitting diode (LED) package structure, an LED chip need be packaged before the LED chip is used, and the LED chip generates a significant amount of heat when emitting light. Given the heat cannot be dissipated and continues to accumulate in the LED package structure, the temperature of the LED package structure is increasingly raised. As such, the overly heated LED chip may have luminance decay, shortened life span, or even permanent damages. Therefore, heat sinks are usually configured in the existing LED package structure, so as to dissipate heat of the LED chip.
The conventional package carrier is comprised of a plurality of patterned conductive layers and at least one insulation layer. The insulation layer is configured between two adjacent patterned conductive layers for electrical insulation. A thermal-conductive block is fixed onto a bottom surface of the package carrier via an adhesive layer. In most cases, the LED chip is electrically connected to the package carrier, and heat generated by the LED chip can be conducted to the thermal-conductive block through the patterned conductive layers and the insulation layer. Since the thermal conductivity of the adhesive layer and the insulation layer is unfavorable, thermal resistance increases when the heat generated by the LED chip is conducted to the thermal-conductive block through the insulation layer and the adhesive layer, which leads to unsatisfactory heat dissipation. Hence, how to dissipate the heat generated by the LED chip to the external surroundings in an efficient manner has become a focus to researchers and designers in this field.